Rising Obesity Rates in Adolescents, Young Adults Tied to Major Health Complications

New research is shedding light on large portions of obesity-related complications attributable to obesity and overweight in adolescents and young adults in the US, posing important implications for the risk of more severe disease and greater associated costs in adulthood.1

The cross-sectional analysis of 2013-2023 National Health and Nutrition Examination Survey (NHANES) data revealed population prevalences of obesity-related complications ranged from 0.3% for type 2 diabetes in adolescents to 36.4% for liver steatosis in young adults, several of which had statistically significant population attributable fractions (PAFs) due to obesity and/or overweight.1

According to the World Health Organization, in 2022, 1 in 8 people in the world were living with obesity. More than 390 million children and adolescents aged 5–19 years were overweight in 2022, including 160 million who were living with obesity.2

“Obesity and obesity-related conditions have been increasing in US youth,” Ashwin Chetty, Yale School of Medicine, and colleagues wrote.1 “It is unclear to what extent obesity and overweight contribute to the development of obesity-related conditions in US youth.”

To address this knowledge gap, investigators performed a cross-sectional study of pooled data from the 2013-2023 NHANES, focusing specifically on adolescents 12-17 years of age and young adults 18-25 years of age with body mass index (BMI) data, calculated as weight in kilograms divided by height in meters squared. Investigators excluded those with pregnancy and underweight, defined for adolescents as BMI < the fifth percentile for age and sex and for young adults as BMI < 18.5.1

In this population, they calculated the adjusted relative risk of having each obesity-related complication in participants with obesity and in participants with overweight compared to participants with normal BMI, controlling for age, sex, NHANES cycle, insurance status, and self-reported routine health care. Investigators additionally calculated PAFs due to obesity and overweight, defined as the proportion of cases for each obesity-related complication that is attributable to obesity and/or overweight.1

In total, the 2013-2023 NHANES study sample included 4199 adolescents and 3200 young adults, representing 25,171,549 adolescents and 30,957,997 young adults. Among the adolescent group, the weighted mean age was 14.5 (Standard deviation [SD], 1.7) years, 50% were female, and 51% were White. Among the young adults, the weighted mean age was 21.7 (SD, 2.3) years, 47% were female, and 54% were White.1

Among adolescents, 18.7% (95% CI, 17.2%-20.2%) had overweight and 22.3% (95% CI, 20.5%-24.1%) had obesity. Among young adults, 25.8% (95% CI, 23.9%-27.8%) had overweight and 29.7% (95% CI, 26.9%-32.5%) had obesity.1

Investigators noted population prevalences of obesity-related complications ranged from 0.3% for type 2 diabetes in adolescents to 36.4% for liver steatosis in young adults.1

Among adolescents, 6 of the 7 measured obesity-related complications had statistically significant PAFs due to obesity, ranging from 10.2% (95% CI, 5.0%-14.1%) for asthma to 49.6% (95% CI, 48.3%-50.5%) for liver steatosis. Among young adults, 8 of 9 measured obesity-related complications had statistically significant PAFs due to obesity, ranging from 10.4% (95% CI, 0.7%-17.1%) for asthma to 78.9% (95% CI, 47.2%-83.0%) for type 2 diabetes.1

Further analysis revealed statistically significant PAFs due to overweight ranged from 6.2% (95% CI, 1.2%-9.9%) for asthma to 13.1% (95% CI, 10.8%-14.7%) for liver steatosis among adolescents. In young adults, statistically significant PAFs due to overweight ranged from 10.0% (95% CI, 4.7%-13.7%) for hypertension to 21.0% (95% CI, 18.4%- 22.6%) for liver steatosis.1

“Large portions of obesity-related complications in US adolescents and young adults may be attributable to obesity and, to a lesser extent, overweight,” investigators concluded.1 “These PAFs can inform estimates of the potential impact of expanding access to behavioral, surgical, and pharmacotherapeutic interventions, including glucagon-like peptide-1 receptor agonists, on reducing obesity-related complications in US youth.”

References

1. Chetty AK, Chen AS, Hajduk AM, et al. Proportion of Obesity-Related Conditions Attributable to Obesity and Overweight in US Youth. JAMA Pediatr. doi:10.1001/jamapediatrics.2025.2716

2. World Health Organization. Obesity and overweight. May 7, 2025. Accessed August 25, 2025. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight